Bridging necking and shear-banding mediated tensile failure in glasses

The transition between necking-mediated tensile failure of glasses, at elevated temperatures

and/or low strain-rates, and shear-banding-mediated tensile failure, at low temperatures and/or

high strain-rates, is investigated using tensile experiments on metallic glasses and atomistic simula-

tions. We experimentally and simulationally show that this transition occurs through a sequence of

macroscopic failure patterns, parametrized by the ultimate tensile strength. Quantitatively analyz-

ing the spatiotemporal dynamics preceding failure, using large scale atomistic simulations corrob-

orated by experimental fractography, reveals how the collective evolution and mutual interaction

of shear-driven plasticity and dilation-driven void formation (cavitation) control the various macro-

scopic failure modes. In particular, we nd that at global failure, the size of the largest cavity in

the loading direction exhibits a nonmonotonic dependence on the temperature at a xed strain rate,

which is rationalized in terms of the interplay between shear- and dilation-driven plasticity. We also

nd that the size of the largest cavity scales with the cross-sectional area of the undeformed sample.

These results shed light on tensile failure of glasses, and highlight the need to develop elasto-plastic

constitutive models of glasses incorporating both shear- and dilation-driven irreversible processes.

See attached file and https://arxiv.org/abs/2212.10102